athena21

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forgive me as I'm sure this question is easy for you guys, but please help me out.

What is the delay between transmission and reception of an FM broadcast sent on a carrier wave of frequency 90 MHz over a distance of 15 km?

A. 5 X 10(-8)
B. 2 X 10(-6)
C. 5 X 10(-5)
D. 2 X 10(4)

Obviously, I can eliminate D. But after that, please help as to how to do this problem and how to go about problems like these on the actual mcat.

thanks!
 

Diogenes

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well, radio waves go 3 X 10^8 m/s, just like all emwaves/photons/light. So 15000 m / 300000000 m/s = 5 X 10^-5.

Is that right people?
 

Diogenes

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The trick to this problem is not to get caught up in the unimportant details. EM waves (light, photons, whatever you like to call it) go the same speed no matter what the frequency. So the fact that they are FM waves at a certain frequncy is just thrown in there to trip you up if you don't know what you are doing.
 
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